M32 - Infectious mononucleosis

Question 1

what is another name for infectious mononucleosis?

Answer 1

“Glandular fever”

-disease of young adults

Question 2

what is the presentation?

Answer 2

• Fever (constant)
• Enlarged lymph nodes
• Sore throat, pharyngitis, tonsillitis
• Malaise, lethargy

Question 3

What percentage of people show normal symptoms?

Answer 3

90%

Question 4

what are other signs and symptoms?

Answer 4

-Jaundice/hepatitis
-Rash
-Haematology:
>Leucocytosis (lymphocytosis)
>Presence of atypical
-lymphocytes in blood film
-Splenomegaly (enlarges)
-Palatal petechiae (bruises)

Question 5

Compare typical and atypical lymphocytes?

Answer 5

-In health-lymphocytes are round and same size as red blood cells
-Atypical lymphocyte-irregular in shape, larger, nuclues is purple and fills half the lyphcyte, blue cytoplasm ( very acidic )
– lots of ribosomes – highly metabolic, - activated
-cytoktoxic T Lymphocytes - seen in viral infections, more than 20% - diagnostic of glandular fever

Question 6

what is the prognosis and complications?

Answer 6

• Protracted but self limiting illness
• Anaemia, thrombocytopenia (shortness of platelets)
• Splenic rupture
• Upper airway obstruction
• Increased risk of lymphoma, especially in immunosuppressed

Question 7

when do the symptoms start/last?

Answer 7

• Onset insidious over several days.
• Fever and pharyngitis lasts 2-4 weeks.
• Lymphadenopathy usually resolves in 4 weeks.
• Lethargy may last longer
• Anaemia is auto-immune and treated by steroids
• Thrombocytopenia usually mild, may not need steroids
• Splenic rupture very rare, but avoid sport for 6 weeks
• URT obstruction occasionally needs steroids or even intubation

Question 8

what causes it?

Answer 8

Epstein-Barr virus (EBV)

Question 9

what virus family does the disease belong to?

Answer 9

• herpes familly

- establishes a persistent infection in epithelial cells (notably in the pharynx)

Question 10

what are the 2 phases of EBV?

Answer 10

• Primary infection in early childhood rarely results in infectious mononucleosis
• Primary infection in those >10 years often causes infectious mononucleosis

Question 11

what is the therapy?

Answer 11

• Bed rest
• Paracetamol
• Avoid sport
• Antivirals not clinically effective
• Corticosteroids may have a role in some complicated cases

Question 12

what is used for laboratory confirmation?

Answer 12

-Heterophile antibody:
>Paul-Bunnell test
>Monospot test (most commonly used) 
-Epstein-Barr virus IgM
-Blood count and film

Question 13

what are the other causes of similar illness?

Answer 13

-Cytomegalovirus
-Toxoplasmosis
-Primary HIV infection:
>a few weeks after initial infection
>“seroconversion illness”